As is well known in the art, DIP devices consisting of a body portion, and attached and depending leads connected thereto for assembly into a PCB or the like, are manufactured with the leads disposed in a particular arrangement adapted for insertion in the predetermined array or pattern of holes or sockets in a PCB. The material of the leads and their connection to, and disposition on, the DIP bodies frequently results in a bending or distortion of the leads due to handling during manufacturing operations.
Since bent or distorted leads of DIP devices will prevent their insertion into predetermined arrays or sockets in a PCB, a need exists for apparatus which determine the integrity of DIP leads prior to insertion on a PCB. As a response to this need, lead straighteners were developed, such as that described in U.S. Pat. No. 3,880,205 for ELECTRONIC COMPONENT LEAD STRAIGHTENING DEVICE AND METHOD, and U.S. Pat. No. 4,481,984 for ELECTRONIC COMPONENT LEAD STRAIGHTENING DEVICE AND METHOD both owned by the assignee of the instant application. Without a device for determining lead integrity, proper orientation of DIP leads could only be assured by passing every DIP device through a lead straightening apparatus prior to insertion on a PCB.
Consequently, a device for determining lead integrity prior to the straightening operation was developed. This device is described in U.S. patent application Ser. No. 648,872 for APPARATUS AND METHOD FOR LEAD INTEGRITY DETERMINATION for DIP devices filed Sept. 10, 1984 and incorporated herein by reference. Such a device provided for the inspection of a large number of DIPs per hour since only those DIP leads requiring straightening and only those DIP leads for which a straightening operation would produce an acceptable result were operated upon. DIP devices with straight leads were automatically passed to an "accepted" receptacle. DIPs with leads, so bent that correction would not be achieved by a straightening operation, were passed to a "rejected" receptacle.
In this prior device angular deviation of leads was determined through the use of a formula which included distance values between a triangular array of sensors. Such a system necessitated the physical measurement of the actual distance between sensors, which measurement was thereafter entered into the system through a series of electrical switches. This system proved cumbersome and in light of the scale of distance being measured, i.e. thousandths of inches, very time consuming. Additionally, it was found that certain deformities in DIP leads were not being discovered. Such deformities are of the type shown in FIG. 13 wherein the DIP lead is bent at two locations such that the terminal portion of the DIP lead is in parallel mutual relationship with the other DIP leads. However, as can be seen, the spacing between leads is no longer uniform. The bent lead is closer to the one adjacent lead than another lead. The attempted insertion of such a device can only result in failure.
Also in this prior integrity device, DIP leads were made to pass through light transmitted by a series of mirror-like components. Since each of these components was physically mounted with adhesive or the like in a housing, angular deviations would result as well as occasionally impairing the reflective quality of the component by the accidental deposit of adhesive on the reflecting surface.